Paramedic Cardiology Questions and Answers Already Passed

Paramedic Cardiology Questions and Answers Already Passed SA Node Rate 60-100 BPM AV Node Rate 40-60 BPM Bundle of His/Perkinjie Rate 40 BPM Flow of blood through the heart from the body superior and inferior vena cavas right atrium tricuspid valve right ventricle semilunar valve pulmonary artery lungs pulmonary veins left atrium bicuspid valve left ventricle semilunar valve aorta to the body Inotropic Beats Harder Chronotropic Beats Faster Dromotropic Improved contractility "P" Wave the P wave represents the electrical activity associated with the contraction of the atria, or atrial depolarization "P-R" Interval Time required for conduction from the SA node to AV node. The time between atrial and ventricular depolarization. This is normally 0.12 to 0.2 seconds. "Q" Wave The first portion of the QRS complex that is seen with a downward deflection and is usually not obvious on the EKG of the normal heart. Often the first portion of the deflection is positive, signifying no Q wave. This is the beginning of ventricular depolarization. "QRS" Complex Represents ventricle depolarization. The QRS Interval is measured from the start of the Q wave or from the beginning of the R wave if no Q wave is present. If no Q wave is present, a normal QRS interval should be less than 0.12 seconds in all leads. "ST" Segment Indicates that ventricle depolarization is complete and that repolarization is about to begin. Also called early ventricle repolarization. The ST Segment is measured from the end of the QRS to the beginning of the T wave, and represents a portion of ventricular repolarization. The normal segment is usually flat, or isoelectric. The absolute measurement of this segment is not as clinically important as is the configuration, whether depressed or elevated. "T" Wave the T wave represents the electrical recovery of the ventricles, or ventricle repolarization. the muscle cells are recovering in preparation for another impulse "R-R" Interval duration of ventricular cardiac cycle (an indicator of ventricular rate) Cardiac Output heart rate x stroke volume, Total blood volume pumped from the left ventricle per minute. Can be increased by increasing heart rate or stroke volume. SV X HR= CO Stroke Volume the volume of blood pumped out by a ventricle with each heartbeat Pre-load Volume of blood in the ventricles at the end of diastole, immediately before ventricular contraction. After-load the pressure that must be exceeded before ejection of blood from the ventricles can occur Diastole relaxation phase of the cardiac cycle, the widening of the chambers of the heart between two contractions when the chambers fill with blood Systole the contraction of the chambers of the heart (especially the ventricles) to drive blood into the aorta and pulmonary artery Beta 1 located in the heart + ionotrphic and chronotrophic, also in kidneys renin release in blood helping regulation of bp causing vasoconstriction Beta 2 bronchodilation, uterine relaxation, glycogenolysis, vasodialation, skeletal muscle contraction Alpha 1 vasoconstriction, mydriasis, contraction of bladder neck and prostate capsule Alpha 2 Decrease Sympathetic outflow thus Vasodilation and decreased BP. Epinephrine sympathomimetic; elevates heart rate, blood pressure Sympathomimetic denotes mimicking of the actions of the sympathetic nervous system (EPI & Nor-EPI) Sympatholytic drug or other substance that blocks the actions of the sympathetic nervous system (also call antiadrenergic). (Clonidine) Cholinergic DRUGS USED TO DECREASE HEART RATE AND ACT ON SMOOTH AND SKELETAL MUSCLES (Parasympathetic System) Anticholinergic Block the action of acetylcholine in the parasympathetic nervous system; also known as cholinergic blocking agents, antispasmodics, and parasympatholytic agents (Atropine) Sympathetic Nervous System the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations (Fight or Flight) EPI and NorEPI Parasympathetic Nervous System the division of the autonomic nervous system that calms the body, conserving its energy (Feed or Breed) Norepinephrine affects arousal and memory; raises blood pressure by causing blood vessels to become constricted, but also carried by bloodstream to the anterior pituitary which relaxes ACTH thus prolonging stress response (levophed) Atropine anti-cholinergic drug that acts on muscarinic receptors. anti-parasympathetic drug, blocks the Parasympathetic NS not stimulating the Sympathetic NS Bundle Branch Block heart block; occurs when electrical impulse is blocked from traveling down the bundle branches; results in the ventricles beating at a different rate than the atria Right Bundle Branch Block widened QRS (0.12s); double peaked QRS in V1 (best to look in V1 and V2); T wave can look abnormal - inverted (does not indicate ischemia) Right Bundle Branch carry electricity through right ventricle 20 - 40 bpm Left Bundle Branch carries electricity through left ventricle 20 - 40 bpm Right Coronary Artery supplies blood to right atrium, portions of both ventricles and cells of AV nodes and SA node. Left Coronary Artery Branches into two arteries: 1. Anterior interventricular artery - also called the left anterior descending artery, supplies the anterior surface of both ventricles and most of the interventricular septum 2. Circumflex artery - supplies the left atrium and ventricle SA Node the pace-maker of the heart; where the impulse conduction of the heart usually starts; located in the top of the right atrium AV Node an area of specialized tissue between the atria and the ventricles of the heart, which conducts the normal electrical impulse from the atria to the ventricles. Perkinje Fibers End of the conduction system; sends impulses through the ventricles, causing them to contract Bundle of HIS neurological fibers, extending from the AV node to the right and left bundle branches, that fire the impulse from the AV node to the Purkinje fibers AV Junction The atrioventricular junction; the portion of the electric conduction system of the heart located in the upper part of the interventricular septum that conducts the excitation impulse from the atria to the bundle of His Atria the upper chambers of the heart Ventricles the two lower chambers of the heart, and they pump blood out to the lungs and body. Sinus Bradycardia When the SA node fires at a rate of less than 60 beats per minute. The P wave and the QRS complex are normal. Sinus Rhythm a heart rhythm established by impulses from the SA node. Irregularities include sinus bradycardia, sinus tachycardia, sinus arrest, and sinus arrhythmia Sinus Tachycardia P Waves present, constant, each constant P Wave is followed by a constant QRS complex (normal width - slim), constant intervals between QRS Complexes are equal, heart rate is 100-150 BPM Atrial Fibrilation irregularly irregular. rate varies and depends on the conduction rate. no identifiable P waves. Baseline shows fibrillartory waves. Atrial Flutter Characterized by a "saw-toothed" wave formation with a slower ventricular rate. The atrial rate generally ranges form 220 to 350 beats/min. Cardioversion may be used. Junctional Rhythm the SA node is nonfunctional, P waves are absent, and heart is paced by the AV node at 40-60 beats/min Accelerated Junctional Rhythm regular rhythm, rate 60-100, p waves inverted or occur before during or after QRS, PRI measured if p before QRS 0.12 Supraventricular Tachycardia A heart rate of over 150 bpm caused above the ventricle, either the atria, SA node, or AV junction. Wolff-Parkinson-White syndrome is a syndrome of pre-excitation of the ventricles of the heart due to an accessory pathway known as the bundle of Kent. This accessory pathway is an abnormal electrical communication from the atria to the ventricles. WPW is a type of atrioventricular reentrant tachycardia. Has a "Delta Wave" on the EKG Ventricular Tachycardia Rhythm: Regular Rate: 100-250 bpm P-waves: Absent PR-Interval: Absent QRS complex: Wide and bizarre *rhythm is unstable, compromises BP and CO Ventricular Fibrilation parts of the myocardium contract random, no blood is pumped, treated with direct-current shock Sinus Arrest The SA node will fail momentarily and will not initiate an impulse Multi-focal Atrial Tachycardia Rate 100-250/bpm P wave two or more ectopic P waves with different morphologies QRS normal Rhythm irregular Lead I records the heart's voltage difference between the right arm and the left arm LA+ RA- Lead II records the dfference between the right arm and left leg; shows the heart's rhythm more clearly than the other two RA- LL+ Lead III records the difference between the left arm and the left leg LA- LL+ V1 Placement fourth intercostal space just right of sternum V2 Placement fourth intercostal space just left of sternum V3 Placement halfway between v2 and v4 V4 Placement fifth intercostal space midclavicular V5 Placement 5th intercostal space, midway between V4 & V6 V6 Placement midaxillary line at the same level as v4 (5th intercostal space) Inferior Leads Leads II,III, aVF Look at electrical activity from the vantage point of the inferior surface Lateral Leads Leads I, aVL, V5 and V6 Look at the electrical activity from the vantage point of the lateral wall of left ventricle. Septal Leads V1 and V2 Look at electrical activity from the vantage point of the septal wall of the ventricles Anterior Leads leads V3 and V4, which are positioned over the front (anterior) of the left ventricle